The cobalt-free spinel LiNi_0.5Mn_1.5O₄ is actively explored as a cost-effective energy storage material. Herein, we report a low-temperature lithiation method to synthesize hierarchical wheatear-like LiNi_0.5Mn_1.5O₄ anchored on active carbon cloth (LNMO@ACC). The LNMO@ACC electrode exhibits a high areal capacitance (1468 mF cm⁻² at 1 mA cm⁻²), superior rate performance (1000 mF cm⁻² at 10 mA cm⁻²), and outstanding cycling stability (82.5% retention after 4000 cycles). The mechanism of Li ions adsorption and diffusion on (111) and (400) lattice planes of LiNi_0.5Mn_1.5O₄ is explained by density functional theory (DFT) calculations. The asymmetric supercapacitor (ASC) assembled by LNMO@ACC cathode and porous Fe₂O₃@ACC anode in 1 M LiNO₃ electrolyte achieves a wide potential window of 1.8 V, superior areal capacitance of 851 mF cm⁻², high energy density of 5.87 mWh cm⁻³ at a power density of 14.17 mW cm⁻³ and excellent cycle stability (retention of 88.6% after 8000 cycles at 20 mA cm⁻²). This work contributes a new method for preparing high-performance electrode materials and an effective strategy for high energy and power density supercapacitors by matching cathode and anode materials.

积极探索无钴尖晶石LiNi _0.5 Mn _1.5 O ₄作为一种经济高效的储能材料。本文中，我们报道了一种低温锂化方法，用于合成锚固在活性炭布（LNMO @ ACC）上的分层的麦穗状LiNi _0.5 Mn _1.5 O ₄。所述LNMO @ ACC电极表现出高面积电容（1468μF的厘米^-2在1mA厘米^-2），优异的倍率性能（1000 MF厘米^-2在10mA厘米^-2），和后突出的循环稳定性（82.5％保留4000个周期）。锂离子在LiNi _0.5的（111）和（400）晶面上的吸附和扩散机理Mn _1.5 O ₄由密度泛函理论（DFT）计算解释。由LNMO @ ACC阴极和多孔Fe ₂ O ₃ @ACC阳极在1 M LiNO ₃电解质中组装而成的不对称超级电容器（ASC）实现了1.8 V的宽电位窗口，851 mF cm ^-2的出色面电容，高能量密度功率密度为14.17 mW cm ^-3时为5.87 mWh cm ^-3且具有出色的循环稳定性（在20 mA cm ^-2的8000次循环后保留率为88.6％）。这项工作为制备高性能电极材料提供了一种新方法，并且通过匹配阴极和阳极材料为高能量和功率密度超级电容器提供了有效的策略。